Hierarchical Basis Error Estimators for Raviart -

| We consider mixed nite element discretizations of linear second order elliptic boundary value problems with respect to an adaptively generated hierarchy of possibly highly nonuniform simplicial triangulations. In particular, we present a hierarchical basis error estimator for Raviart-Thomas mixed nite element discretizations of order l on simplicial triangulations. The introduction of the error estimator is based on the principle of defect correction in higher order ansatz spaces. By means of appropriate localization and decoupling techniques of the ux ansatz space, we obtain an easily computable, eecient and reliable a posteriori error estimator for the ux error and for ux and primal error components.